In recent years, usage of a power semiconductor module covers various types and broad range of power devices or apparatuses such as from a home electronic appliance to a railway vehicle, an electric vehicle, an industrial robot, and a power conditioner. With an increase of the usability of the power semiconductor module, its performance enhancement is expected, and characteristics of high frequency, size reduction, and high power are increasingly desired.
On the other hand, with an achievement of high withstand voltage of an IGBT (Insulated Gate Bipolar Transistor) as a switching element, a high withstand-voltage IGBT having a rated voltage equivalent to that of a thyristor is commercially available. The IGBT is capable of operating at a high speed and obtaining a high withstand voltage and a large current capacity in a relatively simple manner, further having an advantage that an input resistance is high and a voltage control can be performed in a simple manner. Therefore, in an application with a high voltage input, such as a railway vehicle, an electric vehicle, and a power conditioner, there are a considerable number of cases where the IGBT is used as a switching element in a power semiconductor module. In practice, there exists a wealth of lineups of power semiconductor modules having the high withstand-voltage capability in which the IGBT is incorporated. As the power semiconductor module of the high withstand-voltage capability in which the IGBT is incorporated, a configuration disclosed in the following Patent Literature 1 has been known, for example.